Experimental Study of Energy Harvesting Flag under the Influence of Wakes / (Record no. 610712)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 03699nam a22001577a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 621 |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Latif, Usman |
| 245 ## - TITLE STATEMENT | |
| Title | Experimental Study of Energy Harvesting Flag under the Influence of Wakes / |
| Statement of responsibility, etc. | Usman Latif |
| 264 ## - PRODUCTION, PUBLICATION, DISTRIBUTION, MANUFACTURE, AND COPYRIGHT NOTICE | |
| Place of production, publication, distribution, manufacture | Islamabad : |
| Name of producer, publisher, distributor, manufacturer | SMME- NUST; |
| Date of production, publication, distribution, manufacture, or copyright notice | 2021. |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 167p. |
| Other physical details | Soft Copy |
| Dimensions | 30cm |
| 500 ## - GENERAL NOTE | |
| General note | In this dissertation, an energy harvesting system based on wake flow energy is proposed<br/>for microelectromechanical devices that require few watts of energy for their operation. A<br/>potential source of small-scale renewable energy that draws a lot of attention is to harvest<br/>energy linking up with the piezo-flag’s vibration which is caused by fluid force on it. The<br/>stability of the structure is depending upon this applied force and at a critical velocity, it starts<br/>to oscillate. To be benefited from this phenomenon a piezoelectric flag is used just like a<br/>cantilever beam and placed in the wake of a bluff body. The piezoelectric flag is excited by the<br/>shedded vortices in the wake region where a continuous energy transfer process, from fluid to<br/>structure, occurs. This oscillation of the piezo flag produces strain energy in the piezo-material<br/>that can be transformed into electrical energy and stored in a battery or directly supply power<br/>to small sensors using an electrical circuit. The flag in the wake of the cylinder was strongly<br/>influenced by the vortices shed from the upstream cylinder under the vortex-vortex and vortexbody interactions. Geometric and flow parameters are optimized for a flexible flag subjected<br/>to flapping. For investigating the effect of critical parameters and interactions between flexible<br/>bodies and vortices, the current study examined the flexible flags in the viscous flow.<br/>Extensive experimentation is performed to see the impact of key parameters along with<br/>the bluff body’s shape change on the energy harvesting from piezoelectric flags. Several crosssections of the bluff body covering hollow, solid, and range of cut angles (α= 0° – 180°) are<br/>studied. Other parameters including the geometry of the bluff body, L/D (ratio of flag’s length<br/>to cylinder diameter), streamwise gap (Gx=S/D, the ratio of the distance between cylinder and<br/>flag to the diameter), flow velocity U and bending rigidity γ are optimized and it is found that<br/>harvested energy is sensitive to these parameters. Particle image velocimetry (PIV) and<br/>videography techniques are used for the bluff body wake and dynamical behavior of piezoflag. However, PIV is done for selective cases but videography is performed for every case.<br/>PIV results show that the variation in the time-mean wake for different bluff bodies has a<br/>significant impact on the energy harvesting system’s performance.<br/>Two different flag configurations are studied to improve the energy harvesting: a single<br/>flag behind different bluff bodies, and two tandem formations behind a hollow inverted Cshape cylinder. Variation in synchronization of wake flow with the flag is found with the<br/>variation in stated parameters which describes the poorly coupled to an optimally coupled<br/>motion state, where the piezo-flag oscillates at the undisturbed wake’s natural frequency.<br/>x<br/>Furthermore, unidirectional and bidirectional bending is found which explained the variations<br/>in the harvested energy. The aim of the wind and hydrodynamic testing is to maximize the<br/>strain/mechanical energy by coupling the unsteady wake flow with the vibration of the piezoflag. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name entry element | PhD in Mechanical Engineering |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Supervisor : Dr. Emad Uddin |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | <a href="http://10.250.8.41:8080/xmlui/handle/123456789/28209">http://10.250.8.41:8080/xmlui/handle/123456789/28209</a> |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Source of classification or shelving scheme | |
| Koha item type | Thesis |
| Withdrawn status | Permanent Location | Current Location | Shelving location | Date acquired | Full call number | Barcode | Koha item type |
|---|---|---|---|---|---|---|---|
| School of Mechanical & Manufacturing Engineering (SMME) | School of Mechanical & Manufacturing Engineering (SMME) | E-Books | 08/01/2024 | 621 | SMME-Phd-14 | Thesis |